Collaboration Case:  Tracking Loop

Description:  The tracking loop is triggered by a timer and is responsible for updating the telescope position using the POM

Package Assignment:  Tracking.

Preconditions: 

• ATCS state is ONLINE TRACKING
• TRS timer is running, UTC is available
• POM is available

Basic Course: 

• Trigger on TRS timer
• ATCS computes new telescope position with Telescope Pointing Machine
  Exception Course: Computation Failure
  Postcondition: New reference position is available
• ATCS sends new reference position to the tracking axes with Axis Position Control
  Exception Course: Command failed
  Postcondition: Telescope to new reference position

Exception Course: Computation Failure

• ATCS Stops Tracking
• ATCS state ONLINE substate ERROR

Exception Course: Command failed

• ATCS Stops Tracking
• ATCS state ONLINE substate ERROR

Postconditions: 

• Telescope is pointing at new reference position
• Telescope coordinates are updated
• ATCS state ONLINE TRACKING

Issues to be Determined or Resolved: 

Notes:See UTs Analysis

Last modified: Thu Jun 28 14:00:22 UTC 2001